kingwl
2.6 KiB
Agent Note: TUI diff context lines stay neutral
Status: implemented
English | 中文
Problem
Result-time filesystem diffs carry the applied change with three surrounding context lines in each FileDiff.oldText and FileDiff.newText. The TUI rendered every old-side row as removed and every new-side row as added, including the identical context present on both sides. A one-line edit therefore appeared as seven removals plus seven additions, and the footer repeated those inflated totals.
Decision
The TUI compares each non-create FileDiff.oldText and FileDiff.newText at render time. Added and removed rows retain their green + and red - markers; equal context rows use the recessed body tone with a neutral two-space prefix. The footer sums only the rows classified as added or removed. A create (oldText: null) continues to classify every non-empty new-content row as added.
This remains a consumer-side interpretation of the existing FileDiff contract. Filesystem tools continue to persist contextual before/after snippets, so other consumers keep their placement context and existing session logs replay with corrected TUI presentation. The TUI uses the same maintained diff package as dsh-tool-fs instead of introducing a second line-diff implementation.
Alternatives considered
Remove context from filesystem result metadata. Rejected: contextual applied hunks are intentional producer output used by capable editors, and changing them would weaken every consumer while leaving old session logs misleading in the TUI.
Extend FileDiff with persisted per-line tags. Rejected: the tags can be derived deterministically from the existing before/after pair; persisting them would widen the cross-package and session-log contract solely for one renderer.
Match equal lines by position without a diff algorithm. Rejected: insertions and deletions shift subsequent context, so positional pairing would misclassify valid hunks.
Consequences
TUI diff cards distinguish evidence-bearing context from the mutation itself, and their +A -R footer reports the actual line delta. Replaying an existing contextual diff gains the corrected rendering without a migration. Rendering performs one additional line comparison per non-create hunk; result-time hunks are already context-bounded, while create cards bypass the comparison.
The focused TUI test covers neutral context and exact totals. The assembled advanced-cards terminal snapshots pin the neutral context style, semantic change colors, and +1 -1 footer through collapsed and expanded card states.